Sewing machine



I5 Sheets-Sheet l Dec. 25, 1945. v H l BAGWELI.

A SEWING MACHINE Filed Nov. 21, 1942 H. L. BAGWELL SEWING MACHINE Dec.25, i945.

Filed Nov. 21', 1942 3 Sheets-Sheet 5 INVENTOR. MRDY LPBGWLL ATTGRE'Y'NGE ,5.9m

Patented Dec. 25, 1945 E zglii SEWING Macnmni Hardy L Bagwell, Ware.Shoala'Sf.`

` Union' Special Machine Company, Chicago,

a. corporation oflllinois ApplicationA November- 2l, 1942",SxexzialsfNn.l 68,439

fclms. f (Clt 'Il'Zl-ZIB This invention' relates to sewing machines andmore particularlyv to improved* devicesz for T. preventingV theoverheating of rotary hooks employed.

in lockstitch machines.

A primary object ofthe inventionhasl been-to provide a simple and"inexpensive construction. which is economical in use, for directing 'astream of cooling ai-'r` a'gain'sta rotary hook.Vr Through the use ofthe improved'coolingmeans, the heat generated' between the bearingsurfaces of the rotaryy and stationaryA components of the'hook iseffectively dissipatedand", accordingly',v the permissible speed ofvoperation of' the `mfaachine is increased. The invention is particularlyconcerned with that type'of 'hook ink which a raceway is provided in therotating "componentl tofcooperate with a rib on the stationary bobbinholderI andin which therotating component, or loop taker, is revolvedat' twicefthe angular'speedof the needle operating shaft. The `speed ofoperation of such machines is' frequentlyv limited by the tendency ofthe hook to overheat, with the result' that its temper is ,dfrav'vny andthe device rendered useless. r

An vimportant feature of the invention is the provision of control meansby which the delivery of air for hook coolingpurposes is made responsiveto the actual operation of the sewing instrumentalities of the machine.Toward thisA end connections are provided from the treadle whichcontrols the operation of the sewingA machine for simultaneouslycontrolling a valve in the air supply line.

Other objects, features and advantagesv of the invention will appearfrom a detailed vdescription of an illustrative form of the same whichwillnot be given in conjunction with the accompanying drawings, inwhich:

Fig. I is a perspective view showin'g'a sewing machine and its operatingandl controlling de-V vices mountedv on a table, all constructed andarranged in accordance with the invention.

Fig. II is a View showing the sewingv machine largely in side elevationbut with a portion in vertical section along'the axisI of the rotaryhook.

Fig. III is an enlarged',l detail Viewr in side elevation, showing theaircontrol valve and its supporting and operating means, and' Y Fig. IVis a vertical section through the aircontrol valve along the line IV-IVof'Fig. III.

Referring now to the drawings', a sewing machine I, ofv any suitableconstruction, is mounted upon a table I I or other appropriate support.Beneath the top of" the table'there is mounted a driving unitcomprising* an electric* motor I2 and.a;clutclfr-I3- 'Ehese maybe'oi'any'known and appropriate. construction, such as disclosedin thepatenttdfPeetset al., No. 2,004,055-, granted June 4, 1935, or in theapplication of LeVesconte et' al.; Ser'. No... 449,196-, filed June4 30,1942;- .Associ'atedwiith'the; clutchz'is a pulley I4 which'is adapted tobedriven-by the motor I2 whenever the clutch isiengaged. Engagement ofvthe clutch? may' suitably be effected bythe. rocking/of' an armIST-which isi'adapted to be: drawn downwardly' byv a rod3I6=connectedatl I1 with a treadie. I'piv'- otally carriedby" a frame orbracket .I9 on the floorlb'eneath the sewing machine` Theconnecftionbetween the rodi and' the'v arm I5 may be madeofayi'elding character, bythe provision of springs 20. A spring', not shown but formingv part ofthe clutch unit,- serves' to normally retain the rodv IG and the treadlelid in theposition indicated in Fig.v I, in whichv the'l clutch is.`disengaged andthe machne'is idle. The' motor `I 2, however, 'may be inoperation at this timeV due to the Aclosing of'a control switch' 2 I. Abelt 22 connected'with theY pulley'I-I and passing'upwardly-through aslot Z3 in theftableis'connected' withfa combinedhand'wheel and pulley 24': carried` bythe main `drive shaft of the' Isewing machine.Accordingly, whenever the treadle 'is operated to engage the clutch, thesewingmachline will begdiiventov effect the de'- siredstitching. -v

Forpurposesof illustrationa sewing machine of the type disclosedthe-patent to Christensen, No: 2,1135572fgrantedlApril' 12, 1'938, hasbeen se'- lectedf; This ymay' comprisel a main lbase. portion 25,? avvertical"standard 26?, and an overhanging arm- 21 'projecting laterallyfrom the upper end of the' standard-and extendingA over the Worksupporting! surface 'of fthe'base^25.' The overhanging armmmay beprovided at its end with ai needle head' 2U c'arrynga needle'A bar 2'9,withoneor moreneedles'il, foi-'vertical reciprocation |by'y aJp`propria-tei connections from the main vdriving sha-ftof the' InachirieiA presser bar" 31 carrying a presser 'foot 3l-at its lower end' isspringurged downwardlyirr ai conventional manner to retain the-work'aganst'thework( support and' in cooperative relation with: worl;`feeding means, Suit'- able connecztionsy are provided from the maindrive/shaft to-a'shai-'tf-Sin theba'se ofthe-"maehi-ne; 'theflattershaft being'connected appro# pri'ately"with"thework.4 feeding devicesandthe rotary'hook-i' The' latter 'may comprise a rotating component 3'4'whchisi secured to a shaft 35 mounted'inil'a. bearing sleeve 36 carriedbythe base ofthe machine. Gearing. 3l serves; to connect the shattSfwith `shaft .33: thea ratio lof the Cil tion of the raceway betweenthe rotating and stationary components of the hook and this maypin 54 isenlarged and is normally retained by the lower Wall 55 of the valve.Axially in line with the pin 54 is a closure element 51 having a conicalportion arranged to cooperate with a conical seat in an intermediatepartition 58 in the valve housing. This partition serves to divide theinterior of the valve housing into two chambers, including an inletvchamber 59 and an outlet chamberv 60. A spring 65I, surrounding theAstem of the element 51 and cooperating at one end with the enlargedclosure portion of the latter and at the opposite end with a cap 62 atcomprise a conduit 39 adapted to deliver lubricant from an oil cup,suitably positioned adjacentthe standard 25, to a cap 40 mounted-,uponor forming a part of a bearing for the inner end of the hook shaft. Thelatter may suitably be provided with an axial bore, as disclosed 'inthe" patent to Smith, No. 2,089,167, granted August 3, 1937,

through which the lubricant is delivered to the v raceway. For furtherdetails as to the construction ofthe foregoing features of the machine,lreference may be had to said Christensen and Smith patents.

When the raceway is properlylubricated, the hook, and hence the machine,may be operated at a higher speed without overheating than when nolubrication is provided. However, even with proper lubrication, thetemperature of the hook will rise materially in the formation of longseams at speeds of the character now commonly employed. For the purposeof dissipating this heat and thus enabling operation at still higherspeeds, air derived from any suitable source is directed in appropriatevolume againstthe base or inner surface oiv `the hook.l To accomplishthis, a pipe line 4! may be provided, this being arranged to deliver airfrom a compressor unit, or a tank containing compressed air, or .thelike, to a valve 42 mounted on a frame 43` secured vto the floor beneaththe work table I I. From the opposite side of the valve a pipe 44delivers the air, when the valve is open, to a hose line 45 having itsdischarge end 45 positioned in rear of and slightly below the rotaryhook, as indicated in Fig. II. Thus, whenever the valve 42 is opened,air will .be blown across the vback of the rotary component of the hook,and into the interior of the same as the openings in its wall pass theend of the hose, and will thereby produce a desired cooling eiTect. Itwill be understood that if necessary, the air may be cooled aftercompression and before delivery to the hook. By delivering the airagainst and into the hook in the indicated rmanner. disturbance of thethread loop formed about the bobbin case in the-course of stitchformation is avoided, or at least reduced toaminimum. Y l

For the purpose of operating the; valve 42, a lever 41 is provided, this-being pivoted upon a pin 48 carried by a forked portion of a bracket 49which is secured to an outwardly bent 4portion 50 of thel frame 43.l Thevalve, the bracket 49, and the supporting frame are preferably securedtogether by providing the valve with a downward'- ly extending, threadedstem 5I jwhich passes through an aperture in the portion 50 of the frameand through an aperture in a horizontal portion of the bracket 49.Beneath the latter is a nut 52 which retains the parts vinassernbledrelation. A cap member 53, beneath the nut 52, senves both as a lock nutfor the latter and as a guide for the lower end of a pin 54 whichextends axially through the stem 5l and isl slidable freelytherein. Theupper vend 55 ofthe the top of the inlet chamber of the valve, servesnormally to hold the valve in closed condition. However, when the lever41 is rocked clockwise (Fig. III), extension 63 thereof engages thelower end of pin 54 and the latter, in turn, engages the element 51 andraises it from its seat, against the action of spring 6|. Rocking of thelever 41, for this purpose, is accomplished by the engagement of therearward portion of the treadle i8 with an adjustable screw 64 mountedon the lever adjacent its forward end. By properly adjusting the screw64, the time of engagement thereof by the treadle may .be varied, asdesired, to suit particular requirements. Ordinarily the adjustmentshould be such that the screw will be engaged and the valve operatedjust as the clutch is engaged to cause operation of the sewing machine.However, if desired, the adjustment may be such as to cause opening ofthe valve either before or after the clutch has been fully engaged. Inany event, however, the Opening of the valve to deliver cooling air tothe hook will occur as an incident to the operation of the hook and theydelivery of air will continue only so long as the hook remains inoperation or, possibly, -a brief interval thereafter. Wastage of air,which would result from a continuous flow even during brief idle periodsin the operation of the machine, is thus avoided.l Adequate cooling iseffected, particularly with the air under substantial pressure, to allowthe desired increase in speed of operation of the machine.

The operationof the machine is believed to be clear from the foregoingso that a rsum is unnecessary. Y

While a specific embodiment of the invention has been described inconsiderable detail it will be understood that numerous changes may bemade in the construction and arrangement of the several parts withoutdeparting from the general principles and scope of the invention.

-What I claim is:

1. In apparatus of the class described a lockstitch sewing machinehaving a rot-ary hook, power operated means for driving said machine,manually controlled means for delivering power to said power operatedmeans, a treadle having a substantial range of movement for controllingthe operation of said machine by said power operated means, means fordelivering a blast of air against said rotary hook, a valveforcontrolling the operation of said air delivering means, an operatinglever connected with vsaid valve, and Iadjustable means on said leverarranged to be engaged by said treadle at a selected point in its rangeof movement to open saidvalve as an incident to operation of themachine, said means being capableof adjustment to bring about opening oisaid valve prior to engagement of the clutch.

2. In apparatus ofthe class described a lockstitch sewing machine havinga rotary hook, said hook having rotating :and stationaryy components inbearing` engagement, the rotating component having a base with openingsinto the interior thereof and being given two revolutions for each cycleof operation of the machine, a motor and clutch unit for driving saidmachine, manually controlledY means for supplying current to said motor,a treadle, connections from said treadle for controlling the engagementandgdisengagement of said clutch, means for delivering air underpressure from an air line to said hook and directing the same upwardlyand transversely across the base of the rotating component at a pointrelatively close thereto, a valve `for controlling the delivery of airby said means, and means for opening said valve in response to operationof said treadle to engage said clutch.

3. In apparatus of the class described a locksttch sewing machine havingla rotary hook, said hook having rotating and stationary components inbearing engagement, the rotating component being given two revolutionsfor each cycle of operation'of the machine, a motor and clutch unit fordriving said machine, manually controlled means for supplying current tosaid motor, a treadl, yielding connections from said treadle forcontrolling the engagement and disengagement of said clutch, means fordelivering air under substantial pressure to a point closely adjacent tosaid hoo-k and directing the same across the base of the lrotatingcomponent, a valve for controlling the delivery of air by said means,and adjustable operating means for said valve arranged to be operated bysaid treadle in variable relation to and as an incident to theengagement of said clutch, said means being capable of adjustment tobring about opening 'of the valve prior to engagement of the clutch.

HARDY L. BAGWELL.

